Motorcycle transmission featuring reverse gear

Abstract

The invention provides a constant mesh reverse gear operable by a standard rotary shift drum and fork system which is located within the engine casing along with from 3-5 forward gears of the motorcycle transmission. The reverse gear is mounted on the countershaft and engages an idler mounted on its own separate shaft in engagement with a main shaft reverse gear. The idler pin is secured between a pair of plates mounted on the transmission endplate. These plates also have apertures therein to receive the main shaft and countershaft. A standard toe-operated shift lever engages a shift arm which in turn engages a pawl and cam plate assembly for rotating the rotary shift drum. The shift forks are operated by pins riding in cam grooves on the rotary shift drum. An indicator plate on the cam plate assembly contains a contact boss. The contact boss engages electrical contacts in the rear of the engine casing so that the engagement of the transmission in reverse gear may be positively indicated. In turn, these contacts activate both a back-up beeper and back-up lights so that both the rider and pedestrians will be aware that the machine is in reverse gear, ready to be backed up. In the preferred embodiment shown, four forward gears, neutral and reverse, are provided.

I claim: 
     
       1. In a constant mesh gear train assembly for a motorcycle type engine having a main shaft and a countershaft with a plurality of alternate internally splined and freely rotating forward gears, the improvement which comprises in operative combination: (a) a main shaft reverse gear having means for engagement with said main shaft to permit transfer of power between said main shaft and said main shaft reverse gear;   (b) a countershaft reverse gear mounted to freely rotate on said countershaft, disposed with its gear teeth spaced from the gear teeth of said main shaft reverse gear;   (c) said countershaft reverse gear having means for engagement with at least one adjacent gear mounted on said countershaft;   (d) said countershaft adjacent gear having means for engagement with said countershaft to permit transfer of power between said countershaft and said adjacent gear;   (e) means for selectively shifting said countershaft adjacent gear into engagement with said countershaft reverse gear;   (f) a reverse idler gear having means for maintaining the teeth thereof in continuous rotatable mesh with the teeth of both said main and countershaft reverse gears to transfer power therebetween so that both said main and countershaft reverse gears rotate in the same direction; thereby providing reverse gearing throughout the full range of engine power.   
     
     
       2. A gear assembly as in claim 1 which includes: (a) at least three forward gears.   
     
     
       3. A gear assembly as in claim 2 wherein: (a) said shaft means includes means for indicating reverse gear engagement.   
     
     
       4. A gear assembly as in claim 3 wherein: (a) said indicator means includes an indicator plate having means for selectively engaging an electrical contact when said countershaft reverse gear is in engagement with said adjacent countershaft gear.   
     
     
       5. A gear assembly as in claim 4 wherein: (a) said electrical contact actuates a reverse dash light, a reverse beeper, and a back-up light.   
     
     
       6. A gear assembly as in claim 5 which includes: (a) at least four forward gears.   
     
     
       7. A gear assembly as in claim 6 wherein: (a) said forward gears include first through fourth gears;   (b) said adjacent countershaft gear is a third forward gear splined to said countershaft and meshing with a freely rotating main shaft third gear;   (c) said main shaft third gear is adjacent to said main shaft reverse gear and selectively engageable with an adjacent main shaft second gear;   (d) said main shaft second gear is splined to said main shaft and in engagement with shift means for selectively moving it into contact with said main shaft third gear and an adjacent freely rotatable main shaft fourth gear;   (e) a main shaft first gear splined to said main shaft disposed adjacent said main shaft fourth gear;   (f) said main shaft second, main shaft fourth and main shaft first gears being in meshing engagement with corresponding countershaft second, fourth and first gears;   (g) said countershaft fourth gear being splined to said countershaft and selectively engageable with said countershaft first gear;   (h) means for selectively shifting said countershaft second gear into engagement with said countershaft third gear and said countershaft fourth gear into engagement with said countershaft first gear.   
     
     
       8. A gear assembly as in claim 2 wherein: (a) said idler gear mesh maintaining means includes an idler shaft on which said idler gear is rotatably mounted.   
     
     
       9. A gear assembly as in claim 8 wherein: (a) said idler shaft is mounted between a pair of plates securing the ends of said shaft, and having apertures therein for receiving therethrough said main shaft and said countershaft.   
     
     
       10. A gear assembly as in claim 9 which includes: (a) at least four forward gears.   
     
     
       11. A gear assembly as in claim 10 wherein: (a) said forward gears include first through fourth gears;   (b) said adjacent countershaft gear is a third forward gear splined to said countershaft and meshing with a freely rotating main shaft third gear;   (c) said main shaft third gear is adjacent to said main shaft reverse gear and selectively engageable with an adjacent main shaft second gear;   (d) said main shaft second gear is splined to said main shaft and in engagement with shift means for selectively moving it into contact with said main shaft third gear and an adjacent freely rotatable main shaft fourth gear;   (e) a main shaft first gear splined to said main shaft disposed adjacent said main shaft fourth gear;   (f) said main shaft second, main shaft fourth and main shaft first gears being in meshing engagement with corresponding countershaft second, fourth and first gears;   (g) said countershaft fourth gear being splined to said countershaft and selectively engageable with said countershaft first gear;   (h) means for selectively shifting said countershaft second gear into engagement with said countershaft third gear and said countershaft fourth gear into engagement with said countershaft first gear.   
     
     
       12. A gear assembly as in claim 2 which includes: (a) at least four forward gears.   
     
     
       13. A gear assembly as in claim 12 wherein: (a) said forward gears include first through fourth gears;   (b) said adjacent countershaft gear is a third forward gear splined to said countershaft and meshing with a freely rotating main shaft third gear;   (c) said main shaft third gear is adjacent to said main shaft reverse gear and selectively engageable with an adjacent main shaft second gear;   (d) said main shaft second gear is splined to said main shaft and in engagement with shift means for selectively moving it into contact with said main shaft third gear and an adjacent freely rotatable main shaft fourth gear;   (e) a main shaft first gear splined to said main shaft disposed adjacent said main shaft fourth gear;   (f) said main shaft second, main shaft fourth and main shaft first gears being in meshing engagement with corresponding countershaft second, fourth and first gears;   (g) said countershaft fourth gear being splined to said countershaft and selectively engageable with said countershaft first gear;   (h) means for selectively shifting said countershaft second gear into engagement with said countershaft third gear and said countershaft fourth gear into engagement with said countershaft first gear.   
     
     
       14. A gear assembly as in claim 13 wherein: (a) said idler gear mesh maintaining means includes an idler shaft on which said idler gear is rotatably mounted.   
     
     
       15. A gear assembly as in claim 14 wherein: (a) said idler shaft is mounted between a pair of plates securing the ends of said shaft, and having apertures therein for receiving therethrough said main shaft and said countershaft.   
     
     
       16. A gear assembly as in claim 15 wherein: (a) said shift means includes means for indicating reverse gear engagement.   
     
     
       17. A gear assembly as in claim 16 wherein: (a) said indicator means includes an indicator plate having means for selectively engaging an electrical contact when said countershaft reverse gear is in engagement with said adjacent countershaft gear.   
     
     
       18. A gear assembly as in claim 17 wherein: (a) said electrical contact actuates a reverse dash light, a reverse beeper, and a back-up light.   
     
     
       19. A gear assembly as in claim 1 which is disposed in a motorcycle engine crankcase. 
     
     
       20. A gear assembly as in claim 7 which is disposed in a motorcycle engine crankcase. 
     
     
       21. A gear assembly as in claim 11 which is disposed in a motorcycle engine crankcase. 
     
     
       22. A gear assembly as in claim 18 which is disposed in a motorcycle engine crankcase. 
     
     
       23. A motorcycle having an engine in which the gear train is the gear train of claim 1. 
     
     
       24. A motorcycle having an engine in which the gear train is the gear train of claim 7. 
     
     
       25. A motorcycle having an engine in which the gear train is the gear train of claim 11. 
     
     
       26. A motorcycle having an engine in which the gear train is the gear train of claim 18.